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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#define INITGUID
#include "mozilla/mscom/WeakRef.h"
#include "mozilla/Assertions.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/RefPtr.h"
#include "nsThreadUtils.h"
#include "nsWindowsHelpers.h"
#include "nsProxyRelease.h"
namespace mozilla {
namespace mscom {
WeakReferenceSupport::WeakReferenceSupport(Flags aFlags)
: mRefCnt(1)
, mFlags(aFlags)
{
::InitializeCriticalSectionAndSpinCount(&mCS, 4000);
}
WeakReferenceSupport::~WeakReferenceSupport()
{
MOZ_ASSERT(mWeakRefs.IsEmpty());
::DeleteCriticalSection(&mCS);
}
HRESULT
WeakReferenceSupport::QueryInterface(REFIID riid, void** ppv)
{
AutoCriticalSection lock(&mCS);
RefPtr<IUnknown> punk;
if (!ppv) {
return E_INVALIDARG;
}
*ppv = nullptr;
// Raise the refcount for stabilization purposes during aggregation
RefPtr<IUnknown> kungFuDeathGrip(static_cast<IUnknown*>(this));
if (riid == IID_IUnknown || riid == IID_IWeakReferenceSource) {
punk = static_cast<IUnknown*>(this);
} else {
HRESULT hr = ThreadSafeQueryInterface(riid, getter_AddRefs(punk));
if (FAILED(hr)) {
return hr;
}
}
if (!punk) {
return E_NOINTERFACE;
}
punk.forget(ppv);
return S_OK;
}
ULONG
WeakReferenceSupport::AddRef()
{
AutoCriticalSection lock(&mCS);
return ++mRefCnt;
}
ULONG
WeakReferenceSupport::Release()
{
ULONG newRefCnt;
{ // Scope for lock
AutoCriticalSection lock(&mCS);
newRefCnt = --mRefCnt;
if (newRefCnt == 0) {
ClearWeakRefs();
}
}
if (newRefCnt == 0) {
if (mFlags != Flags::eDestroyOnMainThread || NS_IsMainThread()) {
delete this;
} else {
// We need to delete this object on the main thread, but we aren't on the
// main thread right now, so we send a reference to ourselves to the main
// thread to be re-released there.
RefPtr<WeakReferenceSupport> self = this;
NS_ReleaseOnMainThread(self.forget());
}
}
return newRefCnt;
}
void
WeakReferenceSupport::ClearWeakRefs()
{
for (uint32_t i = 0, len = mWeakRefs.Length(); i < len; ++i) {
mWeakRefs[i]->Clear();
mWeakRefs[i]->Release();
}
mWeakRefs.Clear();
}
HRESULT
WeakReferenceSupport::GetWeakReference(IWeakReference** aOutWeakRef)
{
if (!aOutWeakRef) {
return E_INVALIDARG;
}
*aOutWeakRef = nullptr;
AutoCriticalSection lock(&mCS);
RefPtr<WeakRef> weakRef = MakeAndAddRef<WeakRef>(this);
HRESULT hr = weakRef->QueryInterface(IID_IWeakReference, (void**)aOutWeakRef);
if (FAILED(hr)) {
return hr;
}
mWeakRefs.AppendElement(weakRef.get());
weakRef->AddRef();
return S_OK;
}
WeakRef::WeakRef(WeakReferenceSupport* aSupport)
: mRefCnt(1)
, mMutex("mozilla::mscom::WeakRef::mMutex")
, mSupport(aSupport)
{
MOZ_ASSERT(aSupport);
}
HRESULT
WeakRef::QueryInterface(REFIID riid, void** ppv)
{
IUnknown* punk = nullptr;
if (!ppv) {
return E_INVALIDARG;
}
if (riid == IID_IUnknown || riid == IID_IWeakReference) {
punk = static_cast<IUnknown*>(this);
}
*ppv = punk;
if (!punk) {
return E_NOINTERFACE;
}
punk->AddRef();
return S_OK;
}
ULONG
WeakRef::AddRef()
{
return (ULONG) InterlockedIncrement((LONG*)&mRefCnt);
}
ULONG
WeakRef::Release()
{
ULONG newRefCnt = (ULONG) InterlockedDecrement((LONG*)&mRefCnt);
if (newRefCnt == 0) {
delete this;
}
return newRefCnt;
}
HRESULT
WeakRef::Resolve(REFIID aIid, void** aOutStrongReference)
{
MutexAutoLock lock(mMutex);
if (!mSupport) {
return E_FAIL;
}
return mSupport->QueryInterface(aIid, aOutStrongReference);
}
void
WeakRef::Clear()
{
MutexAutoLock lock(mMutex);
MOZ_ASSERT(mSupport);
mSupport = nullptr;
}
} // namespace mscom
} // namespace mozilla
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